The Smell of Molten Projects in the Morning
Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Electrical & Electronic gadgets
I described how to take advantage of Living in the Golden Age of Electronic Making for HVOpen:
Although you don’t get my patter, perhaps the linkies will make up for the silence:
I filled a table with Show-n-Tell widgets and a good time was had by all: hardly anybody fell asleep.
[Update: The talk addressed folks interested in starting out with electronic projects who have no test equipment at all. The choices would be different for other audiences, but … boat anchors aren’t appropriate here.]
The ANENG AN8008 / AN8009 multimeters have 3.6×10 mm ceramic fuses on their inputs:
Based on past experience, at some point over the next year or five, I’ll forget to plug the hot probe back in the voltage hole before measuring a power supply:
Whereupon the fuse will blow.
So, for about five bucks, a bag of 10 A and 0.5 A axial lead fast-blow glass fuses just arrived from halfway around the planet:
They have the right body size and, in this application, fine points concerning current ratings and cartridge composition don’t make much difference. If I actually need one, I’ll snip off the leads, jam it in the holder, and move on.
After converting another fluorescent shoplight into an LED fixture, I tested its capacitors:
The ESR02 reports one as a 4.8 µF capacitor, the other as a “defective part” with a 4 kΩ resistance. Having a cap fail by turning into a resistor is surprising; I’m more surprised it didn’t simply burn up.
They’re visually indistinguishable, of course.
Installing the Xiaomi Dafang Hacks firmware requires an MicroSD card in each camera and, my previous stock having run low, four more just arrived:
Prices have collapsed to the point where known-good (all four passed f3probe testing) cards direct from Samsung (as opposed to Amazon’s “commingled inventory” counterfeit situation) now cost $12-ish each with free shipping.
After I finish fiddling with the first camera, I’ll copy its card onto these four, unique-ify the IP addresses / hostnames /suchlike, and bring ’em all online.
With six new 18500 lithium cells in hand, I rebuilt the three weakest NP-FM50 packs.
The Sherline CNC mill setup for sawing around the midline:
Adjust the saw to cut along the seam, set X=0 at the surface, jog to about X+0.7 mm, jog the saw along the seam, then repeat for the other three sides. No real CNC involved, but it’s much easier than sawing or breaking through the seam by hand.
These two packs came with the camera:
The cells have only lot numbers, no manufacturer ID. Wikipedia sayeth Sony Fukushima started in 2000; perhaps these were early production units with no branding.
The center strap running the length of the pack didn’t seem long enough, because I mistakenly thought I’d straightened its end while unsoldering it. As it happens, the end was straight and secured to the PCB by structural solder:
Moral of the story: pay attention, dammit!
The other end of the center strap required a snippet of tin strip to reach the tabs:
Aligning the cells that way allowed me to just bend the other tabs over the PCB pads and solder them in place:
Then a strip of Kapton tape across the kerf holds the case together well enough to survive our gentle usage:
The battery packs require a brief stay in the charger to reset the PCB’s lockout circuitry, after which they work fine:
The two oldest batteries (OEM 2003 A and OEM 2003 B) have new identities to suit their new innards: 2019 E and 2019 F. The DOA eBay battery retains its 2019 D label after the rebuild, as there’s little room for confusion.
Admittedly, it’d be easier / cheaper / faster to buy third-party NP-FM50 packs directly from eBay or Amazon, but this way I know the cells aren’t complete crap and I get some Quality Shop Time™ out of the deal.
What’s not to like?
According to its description, the Anker USB 3.0 card reader can handle both a MicroSD and a standard SD card at once:
Simultaneously read and write on two cards to save yourself the effort of constant unplugging and re-plugging.
Which looks like this:
After you get used to inserting the SD card downside-up, it fits perfectly. The Kapton tape on the MicroSD card eases extraction from the still finger-dent-less M20 camera mount on the back of my Tour Easy ‘bent.
Plugged into a USB 3.0 port, my file extractor script chugs along at 25.9 MB/s, taking about 18 minutes to transfer 28 GB of video data.
Splurging another eleven bucks for a second reader produces this setup:
After plugging both readers into adjacent USB 3.0 ports, the script transfers files at 46.6 MB/s and copies 28 GB in 10 minutes.
So, yes, the reader can handle two cards at once, but at half the speed.
Not life-changing, but it shows why I like measurements so much …
One of my Wyze V2 cameras either arrived with dead IR hardware or failed early on in its tenure here, but it simply didn’t work in night-vision mode: the IR LEDs didn’t turn on and the IR-cut filter didn’t move. Neither the Official Wyze App nor the Xiaomi-Dafang Hacks firmware had any effect, so I expected a (possibly simple) hardware problem.
The first hint of trouble was finding the case had only one of the two screws securing its bottom lid, with the missing screw having never been installed. Removing the single screw and prying a bit popped the lid, revealing the innards:
The rear panel (on the right) comes off after abusing the snaps holding it to the main case:
That’s best done with a small, designated Prydriver, rather than a screwdriver to which you have a deep emotional attachment.
The corresponding part of the main body shows less abuse:
The black patch is the WiFi antenna, which you must unplug from the top board before going much further.
The small blue wedge below the antenna gave me hope I’d found the root of the IR problem:
Everybody has trouble with those delicate ribbon cable socket clamps!
While I had the case open, I extracted everything and looked it over:
The IR LED soldering left a bit to be desired, so I touched up those joints and washed off most of the flux.
Alas, the IR hardware still didn’t work with everything stuffed back in the case. There are worse things than having a small daylight-only IP camera, though.
So it goes …
The Smell of Molten Projects in the Morning 